The oil fill procedure used in automatic transmissions typically involves adding transmission fluid after the geartrain has been cycled through its various gear states. Thereafter, a dipstick is used to visually determine if the actual oil fill level matches the recommended oil fill level. In some transmissions, side drain holes or a fixed-height standpipe mounted in the bottom of the sump are used to control the oil fill level. In both instances, the drain plugs are installed once the excess oil stops draining out, thereby setting the oil fill level.
As is well known, the oil level in the transmission sump can vary greatly due to changes in the fluid temperature. As such, specific temperature requirements must be accommodated to ensure proper filling of the sump to its recommended oil fill level, particularly during a service operation. These requirements typically include running the vehicle and cycling of the transmission for warming the transmission fluid to a normal operational temperature value prior to measuring and setting the oil fill level. Improper oil fill levels may detrimentally impact the service life of the transmission as well as compromise fuel economy, shift integrity, and other performance related characteristics. Thus, a need exists to provide an apparatus for permitting the sump of a motor vehicle transmission to be filled to its recommended oil fill level in a manner which accommodates variations in the fluid temperature.